drivers/watchdog/sp5100_tco.c

   1 /*
   2  *      sp5100_tco :    TCO timer driver for sp5100 chipsets
   3  *
   4  *      (c) Copyright 2009 Google Inc., All Rights Reserved.
   5  *
   6  *      Based on i8xx_tco.c:
   7  *      (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
   8  *      Reserved.
   9  *                              http://www.kernelconcepts.de
  10  *
  11  *      This program is free software; you can redistribute it and/or
  12  *      modify it under the terms of the GNU General Public License
  13  *      as published by the Free Software Foundation; either version
  14  *      2 of the License, or (at your option) any later version.
  15  *
  16  *      See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
  17  *          AMD Publication 45482 "AMD SB800-Series Southbridges Register
  18  *                                                            Reference Guide"
  19  */
  20
  21 /*
  22  *      Includes, defines, variables, module parameters, ...
  23  */
  24
  25 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  26
  27 #include <linux/module.h>
  28 #include <linux/moduleparam.h>
  29 #include <linux/types.h>
  30 #include <linux/miscdevice.h>
  31 #include <linux/watchdog.h>
  32 #include <linux/init.h>
  33 #include <linux/fs.h>
  34 #include <linux/pci.h>
  35 #include <linux/ioport.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/uaccess.h>
  38 #include <linux/io.h>
  39
  40 #include "sp5100_tco.h"
  41
  42 /* Module and version information */
  43 #define TCO_VERSION "0.05"
  44 #define TCO_MODULE_NAME "SP5100 TCO timer"
  45 #define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
  46
  47 /* internal variables */
  48 static u32 tcobase_phys;
  49 static u32 tco_wdt_fired;
  50 static void __iomem *tcobase;
  51 static unsigned int pm_iobase;
  52 static DEFINE_SPINLOCK(tco_lock);       /* Guards the hardware */
  53 static unsigned long timer_alive;
  54 static char tco_expect_close;
  55 static struct pci_dev *sp5100_tco_pci;
  56
  57 /* the watchdog platform device */
  58 static struct platform_device *sp5100_tco_platform_device;
  59
  60 /* module parameters */
  61
  62 #define WATCHDOG_HEARTBEAT 60   /* 60 sec default heartbeat. */
  63 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
  64 module_param(heartbeat, int, 0);
  65 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
  66                  __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  67
  68 static bool nowayout = WATCHDOG_NOWAYOUT;
  69 module_param(nowayout, bool, 0);
  70 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
  71                 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  72
  73 /*
  74  * Some TCO specific functions
  75  */
  76 static void tco_timer_start(void)
  77 {
  78         u32 val;
  79         unsigned long flags;
  80
  81         spin_lock_irqsave(&tco_lock, flags);
  82         val = readl(SP5100_WDT_CONTROL(tcobase));
  83         val |= SP5100_WDT_START_STOP_BIT;
  84         writel(val, SP5100_WDT_CONTROL(tcobase));
  85         spin_unlock_irqrestore(&tco_lock, flags);
  86 }
  87
  88 static void tco_timer_stop(void)
  89 {
  90         u32 val;
  91         unsigned long flags;
  92
  93         spin_lock_irqsave(&tco_lock, flags);
  94         val = readl(SP5100_WDT_CONTROL(tcobase));
  95         val &= ~SP5100_WDT_START_STOP_BIT;
  96         writel(val, SP5100_WDT_CONTROL(tcobase));
  97         spin_unlock_irqrestore(&tco_lock, flags);
  98 }
  99
 100 static void tco_timer_keepalive(void)
 101 {
 102         u32 val;
 103         unsigned long flags;
 104
 105         spin_lock_irqsave(&tco_lock, flags);
 106         val = readl(SP5100_WDT_CONTROL(tcobase));
 107         val |= SP5100_WDT_TRIGGER_BIT;
 108         writel(val, SP5100_WDT_CONTROL(tcobase));
 109         spin_unlock_irqrestore(&tco_lock, flags);
 110 }
 111
 112 static int tco_timer_set_heartbeat(int t)
 113 {
 114         unsigned long flags;
 115
 116         if (t < 0 || t > 0xffff)
 117                 return -EINVAL;
 118
 119         /* Write new heartbeat to watchdog */
 120         spin_lock_irqsave(&tco_lock, flags);
 121         writel(t, SP5100_WDT_COUNT(tcobase));
 122         spin_unlock_irqrestore(&tco_lock, flags);
 123
 124         heartbeat = t;
 125         return 0;
 126 }
 127
 128 static void tco_timer_enable(void)
 129 {
 130         int val;
 131
 132         if (sp5100_tco_pci->revision >= 0x40) {
 133                 /* For SB800 or later */
 134                 /* Set the Watchdog timer resolution to 1 sec */
 135                 outb(SB800_PM_WATCHDOG_CONFIG, SB800_IO_PM_INDEX_REG);
 136                 val = inb(SB800_IO_PM_DATA_REG);
 137                 val |= SB800_PM_WATCHDOG_SECOND_RES;
 138                 outb(val, SB800_IO_PM_DATA_REG);
 139
 140                 /* Enable watchdog decode bit and watchdog timer */
 141                 outb(SB800_PM_WATCHDOG_CONTROL, SB800_IO_PM_INDEX_REG);
 142                 val = inb(SB800_IO_PM_DATA_REG);
 143                 val |= SB800_PCI_WATCHDOG_DECODE_EN;
 144                 val &= ~SB800_PM_WATCHDOG_DISABLE;
 145                 outb(val, SB800_IO_PM_DATA_REG);
 146         } else {
 147                 /* For SP5100 or SB7x0 */
 148                 /* Enable watchdog decode bit */
 149                 pci_read_config_dword(sp5100_tco_pci,
 150                                       SP5100_PCI_WATCHDOG_MISC_REG,
 151                                       &val);
 152
 153                 val |= SP5100_PCI_WATCHDOG_DECODE_EN;
 154
 155                 pci_write_config_dword(sp5100_tco_pci,
 156                                        SP5100_PCI_WATCHDOG_MISC_REG,
 157                                        val);
 158
 159                 /* Enable Watchdog timer and set the resolution to 1 sec */
 160                 outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
 161                 val = inb(SP5100_IO_PM_DATA_REG);
 162                 val |= SP5100_PM_WATCHDOG_SECOND_RES;
 163                 val &= ~SP5100_PM_WATCHDOG_DISABLE;
 164                 outb(val, SP5100_IO_PM_DATA_REG);
 165         }
 166 }
 167
 168 /*
 169  *      /dev/watchdog handling
 170  */
 171
 172 static int sp5100_tco_open(struct inode *inode, struct file *file)
 173 {
 174         /* /dev/watchdog can only be opened once */
 175         if (test_and_set_bit(0, &timer_alive))
 176                 return -EBUSY;
 177
 178         /* Reload and activate timer */
 179         tco_timer_start();
 180         tco_timer_keepalive();
 181         return nonseekable_open(inode, file);
 182 }
 183
 184 static int sp5100_tco_release(struct inode *inode, struct file *file)
 185 {
 186         /* Shut off the timer. */
 187         if (tco_expect_close == 42) {
 188                 tco_timer_stop();
 189         } else {
 190                 pr_crit("Unexpected close, not stopping watchdog!\n");
 191                 tco_timer_keepalive();
 192         }
 193         clear_bit(0, &timer_alive);
 194         tco_expect_close = 0;
 195         return 0;
 196 }
 197
 198 static ssize_t sp5100_tco_write(struct file *file, const char __user *data,
 199                                 size_t len, loff_t *ppos)
 200 {
 201         /* See if we got the magic character 'V' and reload the timer */
 202         if (len) {
 203                 if (!nowayout) {
 204                         size_t i;
 205
 206                         /* note: just in case someone wrote the magic character
 207                          * five months ago... */
 208                         tco_expect_close = 0;
 209
 210                         /* scan to see whether or not we got the magic character
 211                          */
 212                         for (i = 0; i != len; i++) {
 213                                 char c;
 214                                 if (get_user(c, data + i))
 215                                         return -EFAULT;
 216                                 if (c == 'V')
 217                                         tco_expect_close = 42;
 218                         }
 219                 }
 220
 221                 /* someone wrote to us, we should reload the timer */
 222                 tco_timer_keepalive();
 223         }
 224         return len;
 225 }
 226
 227 static long sp5100_tco_ioctl(struct file *file, unsigned int cmd,
 228                              unsigned long arg)
 229 {
 230         int new_options, retval = -EINVAL;
 231         int new_heartbeat;
 232         void __user *argp = (void __user *)arg;
 233         int __user *p = argp;
 234         static const struct watchdog_info ident = {
 235                 .options =              WDIOF_SETTIMEOUT |
 236                                         WDIOF_KEEPALIVEPING |
 237                                         WDIOF_MAGICCLOSE,
 238                 .firmware_version =     0,
 239                 .identity =             TCO_MODULE_NAME,
 240         };
 241
 242         switch (cmd) {
 243         case WDIOC_GETSUPPORT:
 244                 return copy_to_user(argp, &ident,
 245                         sizeof(ident)) ? -EFAULT : 0;
 246         case WDIOC_GETSTATUS:
 247         case WDIOC_GETBOOTSTATUS:
 248                 return put_user(0, p);
 249         case WDIOC_SETOPTIONS:
 250                 if (get_user(new_options, p))
 251                         return -EFAULT;
 252                 if (new_options & WDIOS_DISABLECARD) {
 253                         tco_timer_stop();
 254                         retval = 0;
 255                 }
 256                 if (new_options & WDIOS_ENABLECARD) {
 257                         tco_timer_start();
 258                         tco_timer_keepalive();
 259                         retval = 0;
 260                 }
 261                 return retval;
 262         case WDIOC_KEEPALIVE:
 263                 tco_timer_keepalive();
 264                 return 0;
 265         case WDIOC_SETTIMEOUT:
 266                 if (get_user(new_heartbeat, p))
 267                         return -EFAULT;
 268                 if (tco_timer_set_heartbeat(new_heartbeat))
 269                         return -EINVAL;
 270                 tco_timer_keepalive();
 271                 /* Fall through */
 272         case WDIOC_GETTIMEOUT:
 273                 return put_user(heartbeat, p);
 274         default:
 275                 return -ENOTTY;
 276         }
 277 }
 278
 279 /*
 280  * Kernel Interfaces
 281  */
 282
 283 static const struct file_operations sp5100_tco_fops = {
 284         .owner =                THIS_MODULE,
 285         .llseek =               no_llseek,
 286         .write =                sp5100_tco_write,
 287         .unlocked_ioctl =       sp5100_tco_ioctl,
 288         .open =                 sp5100_tco_open,
 289         .release =              sp5100_tco_release,
 290 };
 291
 292 static struct miscdevice sp5100_tco_miscdev = {
 293         .minor =        WATCHDOG_MINOR,
 294         .name =         "watchdog",
 295         .fops =         &sp5100_tco_fops,
 296 };
 297
 298 /*
 299  * Data for PCI driver interface
 300  *
 301  * This data only exists for exporting the supported
 302  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 303  * register a pci_driver, because someone else might
 304  * want to register another driver on the same PCI id.
 305  */
 306 static DEFINE_PCI_DEVICE_TABLE(sp5100_tco_pci_tbl) = {
 307         { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
 308           PCI_ANY_ID, },
 309         { 0, },                 /* End of list */
 310 };
 311 MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
 312
 313 /*
 314  * Init & exit routines
 315  */
 316 static unsigned char sp5100_tco_setupdevice(void)
 317 {
 318         struct pci_dev *dev = NULL;
 319         const char *dev_name = NULL;
 320         u32 val;
 321         u32 index_reg, data_reg, base_addr;
 322
 323         /* Match the PCI device */
 324         for_each_pci_dev(dev) {
 325                 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
 326                         sp5100_tco_pci = dev;
 327                         break;
 328                 }
 329         }
 330
 331         if (!sp5100_tco_pci)
 332                 return 0;
 333
 334         pr_info("PCI Revision ID: 0x%x\n", sp5100_tco_pci->revision);
 335
 336         /*
 337          * Determine type of southbridge chipset.
 338          */
 339         if (sp5100_tco_pci->revision >= 0x40) {
 340                 dev_name = SB800_DEVNAME;
 341                 index_reg = SB800_IO_PM_INDEX_REG;
 342                 data_reg = SB800_IO_PM_DATA_REG;
 343                 base_addr = SB800_PM_WATCHDOG_BASE;
 344         } else {
 345                 dev_name = SP5100_DEVNAME;
 346                 index_reg = SP5100_IO_PM_INDEX_REG;
 347                 data_reg = SP5100_IO_PM_DATA_REG;
 348                 base_addr = SP5100_PM_WATCHDOG_BASE;
 349         }
 350
 351         /* Request the IO ports used by this driver */
 352         pm_iobase = SP5100_IO_PM_INDEX_REG;
 353         if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, dev_name)) {
 354                 pr_err("I/O address 0x%04x already in use\n", pm_iobase);
 355                 goto exit;
 356         }
 357
 358         /*
 359          * First, Find the watchdog timer MMIO address from indirect I/O.
 360          */
 361         outb(base_addr+3, index_reg);
 362         val = inb(data_reg);
 363         outb(base_addr+2, index_reg);
 364         val = val << 8 | inb(data_reg);
 365         outb(base_addr+1, index_reg);
 366         val = val << 8 | inb(data_reg);
 367         outb(base_addr+0, index_reg);
 368         /* Low three bits of BASE are reserved */
 369         val = val << 8 | (inb(data_reg) & 0xf8);
 370
 371         pr_debug("Got 0x%04x from indirect I/O\n", val);
 372
 373         /* Check MMIO address conflict */
 374         if (request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
 375                                                                 dev_name))
 376                 goto setup_wdt;
 377         else
 378                 pr_debug("MMIO address 0x%04x already in use\n", val);
 379
 380         /*
 381          * Secondly, Find the watchdog timer MMIO address
 382          * from SBResource_MMIO register.
 383          */
 384         if (sp5100_tco_pci->revision >= 0x40) {
 385                 /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
 386                 outb(SB800_PM_ACPI_MMIO_EN+3, SB800_IO_PM_INDEX_REG);
 387                 val = inb(SB800_IO_PM_DATA_REG);
 388                 outb(SB800_PM_ACPI_MMIO_EN+2, SB800_IO_PM_INDEX_REG);
 389                 val = val << 8 | inb(SB800_IO_PM_DATA_REG);
 390                 outb(SB800_PM_ACPI_MMIO_EN+1, SB800_IO_PM_INDEX_REG);
 391                 val = val << 8 | inb(SB800_IO_PM_DATA_REG);
 392                 outb(SB800_PM_ACPI_MMIO_EN+0, SB800_IO_PM_INDEX_REG);
 393                 val = val << 8 | inb(SB800_IO_PM_DATA_REG);
 394         } else {
 395                 /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
 396                 pci_read_config_dword(sp5100_tco_pci,
 397                                       SP5100_SB_RESOURCE_MMIO_BASE, &val);
 398         }
 399
 400         /* The SBResource_MMIO is enabled and mapped memory space? */
 401         if ((val & (SB800_ACPI_MMIO_DECODE_EN | SB800_ACPI_MMIO_SEL)) ==
 402                                                   SB800_ACPI_MMIO_DECODE_EN) {
 403                 /* Clear unnecessary the low twelve bits */
 404                 val &= ~0xFFF;
 405                 /* Add the Watchdog Timer offset to base address. */
 406                 val += SB800_PM_WDT_MMIO_OFFSET;
 407                 /* Check MMIO address conflict */
 408                 if (request_mem_region_exclusive(val, SP5100_WDT_MEM_MAP_SIZE,
 409                                                                    dev_name)) {
 410                         pr_debug("Got 0x%04x from SBResource_MMIO register\n",
 411                                 val);
 412                         goto setup_wdt;
 413                 } else
 414                         pr_debug("MMIO address 0x%04x already in use\n", val);
 415         } else
 416                 pr_debug("SBResource_MMIO is disabled(0x%04x)\n", val);
 417
 418         pr_notice("failed to find MMIO address, giving up.\n");
 419         goto  unreg_region;
 420
 421 setup_wdt:
 422         tcobase_phys = val;
 423
 424         tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
 425         if (!tcobase) {
 426                 pr_err("failed to get tcobase address\n");
 427                 goto unreg_mem_region;
 428         }
 429
 430         pr_info("Using 0x%04x for watchdog MMIO address\n", val);
 431
 432         /* Setup the watchdog timer */
 433         tco_timer_enable();
 434
 435         /* Check that the watchdog action is set to reset the system */
 436         val = readl(SP5100_WDT_CONTROL(tcobase));
 437         /*
 438          * Save WatchDogFired status, because WatchDogFired flag is
 439          * cleared here.
 440          */
 441         tco_wdt_fired = val & SP5100_PM_WATCHDOG_FIRED;
 442         val &= ~SP5100_PM_WATCHDOG_ACTION_RESET;
 443         writel(val, SP5100_WDT_CONTROL(tcobase));
 444
 445         /* Set a reasonable heartbeat before we stop the timer */
 446         tco_timer_set_heartbeat(heartbeat);
 447
 448         /*
 449          * Stop the TCO before we change anything so we don't race with
 450          * a zeroed timer.
 451          */
 452         tco_timer_stop();
 453
 454         /* Done */
 455         return 1;
 456
 457 unreg_mem_region:
 458         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
 459 unreg_region:
 460         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
 461 exit:
 462         return 0;
 463 }
 464
 465 static int sp5100_tco_init(struct platform_device *dev)
 466 {
 467         int ret;
 468
 469         /*
 470          * Check whether or not the hardware watchdog is there. If found, then
 471          * set it up.
 472          */
 473         if (!sp5100_tco_setupdevice())
 474                 return -ENODEV;
 475
 476         /* Check to see if last reboot was due to watchdog timeout */
 477         pr_info("Last reboot was %striggered by watchdog.\n",
 478                 tco_wdt_fired ? "" : "not ");
 479
 480         /*
 481          * Check that the heartbeat value is within it's range.
 482          * If not, reset to the default.
 483          */
 484         if (tco_timer_set_heartbeat(heartbeat)) {
 485                 heartbeat = WATCHDOG_HEARTBEAT;
 486                 tco_timer_set_heartbeat(heartbeat);
 487         }
 488
 489         ret = misc_register(&sp5100_tco_miscdev);
 490         if (ret != 0) {
 491                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 492                        WATCHDOG_MINOR, ret);
 493                 goto exit;
 494         }
 495
 496         clear_bit(0, &timer_alive);
 497
 498         /* Show module parameters */
 499         pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
 500                 tcobase, heartbeat, nowayout);
 501
 502         return 0;
 503
 504 exit:
 505         iounmap(tcobase);
 506         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
 507         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
 508         return ret;
 509 }
 510
 511 static void sp5100_tco_cleanup(void)
 512 {
 513         /* Stop the timer before we leave */
 514         if (!nowayout)
 515                 tco_timer_stop();
 516
 517         /* Deregister */
 518         misc_deregister(&sp5100_tco_miscdev);
 519         iounmap(tcobase);
 520         release_mem_region(tcobase_phys, SP5100_WDT_MEM_MAP_SIZE);
 521         release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
 522 }
 523
 524 static int sp5100_tco_remove(struct platform_device *dev)
 525 {
 526         if (tcobase)
 527                 sp5100_tco_cleanup();
 528         return 0;
 529 }
 530
 531 static void sp5100_tco_shutdown(struct platform_device *dev)
 532 {
 533         tco_timer_stop();
 534 }
 535
 536 static struct platform_driver sp5100_tco_driver = {
 537         .probe          = sp5100_tco_init,
 538         .remove         = sp5100_tco_remove,
 539         .shutdown       = sp5100_tco_shutdown,
 540         .driver         = {
 541                 .owner  = THIS_MODULE,
 542                 .name   = TCO_MODULE_NAME,
 543         },
 544 };
 545
 546 static int __init sp5100_tco_init_module(void)
 547 {
 548         int err;
 549
 550         pr_info("SP5100/SB800 TCO WatchDog Timer Driver v%s\n", TCO_VERSION);
 551
 552         err = platform_driver_register(&sp5100_tco_driver);
 553         if (err)
 554                 return err;
 555
 556         sp5100_tco_platform_device = platform_device_register_simple(
 557                                         TCO_MODULE_NAME, -1, NULL, 0);
 558         if (IS_ERR(sp5100_tco_platform_device)) {
 559                 err = PTR_ERR(sp5100_tco_platform_device);
 560                 goto unreg_platform_driver;
 561         }
 562
 563         return 0;
 564
 565 unreg_platform_driver:
 566         platform_driver_unregister(&sp5100_tco_driver);
 567         return err;
 568 }
 569
 570 static void __exit sp5100_tco_cleanup_module(void)
 571 {
 572         platform_device_unregister(sp5100_tco_platform_device);
 573         platform_driver_unregister(&sp5100_tco_driver);
 574         pr_info("SP5100/SB800 TCO Watchdog Module Unloaded\n");
 575 }
 576
 577 module_init(sp5100_tco_init_module);
 578 module_exit(sp5100_tco_cleanup_module);
 579
 580 MODULE_AUTHOR("Priyanka Gupta");
 581 MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
 582 MODULE_LICENSE("GPL");
 583 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);